This project is concerned with clinical and theoretical problems arising from brain injury resulting in aphasia and related disorders of higher perceptual motor and cognituve functions. Clinical problems in the current year involve testing the predictive value of the Boston Diagnostic Aphasia Test against independent diagnostic and localizing data. Psycholinguistic problems will include (1) relating auditory comprehension difficulty to phonemic discrimination problems and (2) examining the integrity of semantic fields (tested receptively in relation to word-naming difficulty; (3) examining the effect of aphasia on verbal mediation in a memory task for homophonic and non-homophonic pictures. Studies of brain laterality this year include (1) comparing right and left visual fields in the processing of musical notation (2) comparing reaction times of right and left-handers to randomized unilateral auditory signals.